I always thought they were the sucked-dry shells of the aphids the larvae ate, but shed skins works.

It's a thriving little battleground there ... the various wrens, hummingbirds and verdins have found the buffet.

Could be sucked-dry exoskeletons.

But ladybugs chow down exoskeleton and all.

Lazy, ladybug larvae don't suck on the aphids.....they have chewing mouthparts just like the adults and feast on the whole aphid....like popcorn! ;-)

HERE'S an image from BugGuide.net showing an aphid nearly finished with its molting process. The skin splits along the top and they literally squeeze themselves out....leaving behind a fully formed exoskeleton including legs and antennae!

It may depend on species of ladybug ... I've seen the "Larvae paralyse aphids and suck their body fluids out, generally through a leg or antenna. " statement about some.

Huh?

From:
Natural Enemies of the Southwest : A field guide to the arthropod natural enemies of southwestern field crops by Lydia M. Brown, Peter C. Ellsworth et al.

I would have assumed that bodily fluids meant honeydew. Lazy, I find it very entertaining to imagine a bunch of ladybug larvae hanging out sipping from aphid innards using the legs or antennae as straws!

Honeydew is a readily accessible energy source and I can easily believe that ladybugs of any age would partake. Aphids, as a matter of fact, will produce an extra gluey honeydew as a way to protect themselves from the sippers.

HERE are some more images of aphid instars.